Strigolactone-mediated drought tolerance in maize (Zea mays) seedlings: an omics approach.

Strigolactones (SLs) are newly discovered plant hormones that regulate various aspects of plant growth and development. Their analogs, specifically GR24, have significant potential, including the ability to enhance tolerance to abiotic stresses, especially drought, thereby benefiting plant growth, physiological responses, and developmental processes. In this experiment, maize seedlings were exposed to drought stress at the 6-leaf stage (V6) to investigate mitigation effects following the exogenous application (foliar and soil drench) of GR24 (a strigolactone analog). Physiological analysis showed that drench-applied SL significantly enhanced the activity of antioxidant defense enzymes, including superoxide dismutase, and catalase, leading to reduced malondialdehyde contents and accumulation of hydrogen peroxide (H2O2). Transcriptome analysis was conducted to identify differentially expressed genes (DEGs). Weighted gene co-expression network analysis (WGCNA) was used to cluster genes associated with physiological activity in response to SL application. Based on the co-expression networks, the transcriptomic data were divided into ten modules, with the blue module showing the strongest correlation with physiological parameters. Furthermore, genes related to glutathione peroxidase, succinate dehydrogenase, CAMP-regulated phosphoprotein 19-related protein, and glutamate decarboxylase proteins were identified as key contributors to drought stress mitigation. RT-qPCR analysis was performed to validate the gene significance of the top hub genes.